Continued Loss in Visceral and Intermuscular Adipose Tissue in Weight-Stable Women Following Bariatric Surgery

ObjectiveTo assess changes in total (TAT), subcutaneous (SAT), visceral (VAT), and intermuscular (IMAT) adipose tissue by whole-body MRI before surgery and at 12 months and 24 months post-surgery in a subset of participants of the Longitudinal Assessment of Bariatric Surgery-2. MethodsFrom 0 to 12 months, n=20 females and 3 males; from 12 to 24 months, n=42 females and 7 males. Paired t-tests and GLM repeated measures examined changes in TAT, SAT, VAT, and IMAT at 12 and 24 months, with sex and age as covariates. ResultsChanges from 0 to 12 months included weight (-41.912.1 kg; -36%), TAT (-33.5 +/- 9.6 kg; -56%), SAT (-29.2 +/- 8.2 kg; -55%), VAT (-3.3 +/- 1.6 kg; -73%), and IMAT (-0.99 +/- 0.68 kg; -50%), all P<0.001. In females, from 12 to 24 months, despite relative weight stability (-1.8 +/- 6.5 kg, -2%; P=0.085), VAT (-0.5 +/- 0.7 kg; -30%; P<0.001) and IMAT (-0.2 +/- 0.4 kg; -14%; P=0.012) decreased further. In males, from 12 to 24 months, weight increased (5.1 +/- 5.2 kg; 6%; P=0.04) with no significant changes in TAT or sub-depots. ConclusionsBariatric surgery continues to induce favorable changes in body composition, i.e., persistent adipose tissue loss at 24 months in the absence of further significant weight loss.